AT&T’s CFO John Stephens chose an unusual place to announce that the company would be launching its LTE network this Sunday, Sept. 18. Stephens announced the news at the Bank of America Merrill Lynch Media, Entertainment & Communications conference (BAMLMEC?), which is a conference we’re hearing about for the first time. Where he dropped the bomb doesn’t actually matter. What really matters is that we now have a date for the launch of AT&T’s LTE network.

To start, AT&T will launch in only five markets with just 15 more going live by the end of the year to cover 70 million people. So who are the lucky AT&T customers to have first access to the carrier’s LTE network? Residents of Atlanta, Chicago, Houston, San Antonio, and Dallas will get first dibs. Verizon’s LTE network is currently live in 143 markets and cover over 160 million people, so AT&T has a long way to go.

A little under a month ago, AT&T released two LTE devices, which we thought was a little odd seeing as there was no LTE network for the USBConnect Momentum 4G dongle and the Mobile Hotspot Elevate 4G to run on . The devices still worked but used AT&T’s HSPA+ network, which is not quite 4G. Now the two products can run freely on the LTE network, and actually, that’s all that can work on the network. AT&T doesn’t actually have any LTE smartphones just yet.

AT&T has yet to release any official data on speeds, but AT&T did say its LTE 3G service would be “comparable to Verizon’s LTE 4G network.” Verizon’s network supposedly gets download speeds of 5-Mbps to 12-Mbps and 2-Mbps to 3-Mbps upload speeds.

In addition to the dongle and hotspot mentioned above, AT&T also released the LTE-capable HTC Jetstream tablet at the end of August. Starting at $699.99, the tablet is a little on the pricey side, but it comes with the option of a 3GB per month data plan for $35.

AT&T said it won’t offer any LTE smartphones until the end of 2011 at the earliest, which gives us more reason to believe that the iPhone 5 won’t be equipped for LTE. That being said, AT&T didn’t mention anything about LTE smartphone data pricing. However, it did say that it will charge $50 for 5 GB of data for its data-only LTE devices.